Assisted Living (AL) has grown rapidly over the last 15 years, but little is known about the psychiatric morbidity of AL residents. This resubmission is a five-year continuation of the Maryland Assisted Living Study (1R01 MH60626). MD-AL was a two-year project intended to estimate the prevalence of dementia and psychiatric disorders in a stratified random sample of assisted living residents. By this time, that study has completed assessment of 150 residents, with anticipated final recruitment of 200. Participants undergo a comprehensive evaluation for dementia, a standardized psychiatric examination, and are rated on scales quantifying dementia-associated behavioral disturbances, general medical co-morbidity, functional (IADL and ADL) impairment, quality of life, and caregiver burden. Information is collected on the need for services. Basic data are collected on the AL facility, the resident's primary caregiver and a family informant. The study team has acquired critical experience and assembled a cohort of facilities and residents for further study. Our data provide the first direct estimate of psychiatric morbidity in AL: preliminary analyses indicate that 69% of AL residents suffer from dementia, with 28% suffering from another DSM-IV diagnosis, and cumulative prevalence of dementia or another psychiatric disorder of 81%. Analyses indicate that less than 1/2 of psychiatric morbidity in AL is appropriately detected and managed, and that this morbidity is associated with greater disability and worse life quality. Now the study team proposes to assess longitudinally the impact of dementia and other psychiatric morbidity on two key AL outcomes: quality of life and the ability to age in place. This will be accomplished by continued semi-annual in person follow-up of the original 200 study participants and by the recruitment of 200 more residents who have been admitted to AL in the last 3 months; residents will be followed to death or discharge from AL, or for up to three years. This will permit longitudinal study of the course, detection, and treatment of dementia and other psychiatric disorders in AL residents (Aim 1), the impact of dementia and other psychiatric morbidity, treated and untreated, on quality of life (Aim 2), and time to death or discharge from the facility (Aim 3). Study findings are expected to have a substantial impact in gerontology, geriatric medicine and geriatric psychiatry. They will provide essential information about the consequences of psychiatric morbidity on the ability of assisted living residents (projected to approach 3.9 million by 2025) to age in place. This information is of great interest to healthcare providers, licensing agencies, policy makers, the assisted living industry and the general public. Study findings may affect clinical practices in assisted living resulting in the implementation of assisted living-based screening and treatment programs for dementia and other psychiatric disorders that will benefit residents, and may improve quality of life, and delay discharge.